That smoke smell is coming from a large mulch fire on old mining property

Photographer Scott McIntrye took this video from a helicopter flying over the mulch fire going on in Golden Gate Estates. Big Corkscrew Fire Department responded to a 911 call early Thursday morning.

Big Corkscrew Island Fire District Capt. Eric Watson describes how firefighters responded to and what caused a mulch fire Wednesday night at Environmental Turnkey Solutions' site in Golden Gate Estates. The fire caused the spread of a smoky smell Thursday morning throughout northern Collier County and southern Lee County.

Jacob Carpenter/Naples Daily News

Not even Smokey Bear could prevent this fire.

A massive pile of mulch that caught fire at the site of a former mine in Golden Gate Estates late Wednesday likely self-ignited, spreading a smoky aroma into northern Collier and southern Lee counties for much of Thursday, Big Corkscrew Island Fire District officials said.

The pile, which spanned about 300 feet and reached heights of about 30 feet, likely caught fire due to high heat at the heart of the discarded vegetation, Big Corkscrew Island Fire Capt. Eric Watson said.

"We didn't have any thunderstorms, obviously there's nobody around when it happened, it was behind a locked gate facility," Watson said. "It's probably just natural causes that are the cause of the fire."

Firefighters were called to Environmental Turnkey Solutions' site about two miles north of the Collier County fairgrounds at about 11 p.m. Wednesday, Watson said. The company takes horticultural waste and recycles it into top soil and mulch for farmers and retailers.

Monitoring by firefighters will continue in the coming days, but the company's staff are now handling most of the work. Time, and possibly rains expected Friday and Saturday, will best extinguish the fire.

"It's burned down now and it kind of looks like a mountain range with some peaks and valleys in it," Watson said of the pile.

By Thursday morning, the smoky smell had reached the coastland areas, carried through dry air by high winds. Watson estimated the aroma could linger for about a week, if not longer. A recent mulch fire sparked by ashes from a controlled burn south of Oil Well Road near Ave Maria lingered for two to three weeks, Watson said.

Thursday's fire was contained to the mulch pile. No homes were threatened.

When reached for comment Thursday morning, an Environmental Turnkey Solutions staffer said he didn't know anything about the fire and hung up. Multiple follow-up efforts to reach employees at the North Naples-based company were unsuccessful.

Florida Department of Environmental Protection records show the company is permitted to work at the site. State inspectors most recently reported about the location in February 2013, finding the facility had "adequate fire extinguishers, hoses, and sprinklers to suppress any potential fire that occurs on-site."

Inspectors said the facility met 27 out of 28 safety and environmental requirements. The one unmet requirement — keeping all materials within 50 feet of motorized firefighting equipment — was corrected, state records show.

Mulch fires can present unique challenges, said Tracy McMillion, fire coordinator for the Southwest Florida Public Service Academy, which trains aspiring firefighters. The density of stacked vegetative waste makes it difficult to get water deep into a smoldering pile, McMillion said.

"It takes a lot of time and a lot of resources to put it out," McMillion said. "The easy part is that it's contained, and the other thing along with that is there's not any life safety issues you have to worry about."